This project will be conducted to evaluate the biological significance of alterations in the metabolic control of proline hydroxylase in connective tissue disease. Previous investigations have established that proline hydroxylase activity is elevated in scleraderma and rheumatoid arthritis. Fibroblasts cultured from normal and rheumatoid synovial tissue, explants of granuloma tissue, and explants of liver with fibrosis in vivo will be used to characterize the diseased state in vitro. The time course of the appearance of proline hydroxylase will be determined and compared to the established fibroblast cell lines 3T6 and L929. An enzyme immuno assay will be used to assay for total antigen, and the overall rate of collagen synthesis will be determined through the use of a specific collagenase assay. Extracts and column fractions of cells will be examined for activators of collagen synthesis, and extracts and column fractions of fibrotic liver containing known activators of prolyl hydroxylase and collagen synthesis will be added to cultures to determine changes in sensitivity in diseased cells. Molecular properties and extent of hydroxylation of collagen made by the tissue culture systems will be determined.